The present invention generally relates to an apparatus and system for the production of smooth shaded continuous tone planar images. More specifically, the present invention relates to a program controlled computer system capable of interactive production of user-variable smooth shade planar images incorporating various user-constructed degrade patterns within the planar image.
In the context of the present invention, a smooth shaded continuous tone image comprises at least two spatially discrete and distinctly shaded (or colored) regions separated by a region of transition between the different shades. This transition region is referred to as the "degrade" of the continuous tone planar image and forms a zone of gradual change from one shade to the other. While the following discussion will address various aspects of image "shading", it should be recognized that the same concepts are equally applicable in a multi-color image format.
The planar images as described above play an important role in the Graphic Arts field. These images are characterized by gradually changing shades that are spatially arranged, and more importantly, the absence of sharp breaks or borders in the image. This type of planar image is an ideal background for a more complex, central figure. More specifically, when a graphic artist displays an item having certain commercial or aesthetic attributes, he requires a background that does not distract attention away from the displayed item. The degrade pattern, as background, tends to highlight the central item of the composite rendering in an aesthetically pleasing manner, while focusing the observer's attention onto the central item.
A specific example of such a use exists in the product packaging industry. In this context, the package containing the product will often carry a pictorial representation of the enclosed product on an exposed surface. To draw attention to the pictured product, the entire rendering will include a background with a degrade pattern converging on the central product image. This background becomes a key component in the overall impression desired by the graphic artist, and therefore a suitably large effort is expended in its preparation.
In the past, degrade patterns were created by mechanical application of the desired pattern onto a print receiving surface. One mechanical applicator often used is an "air brush", which operates as an atomizer for applying a fine mist of paint spray, propelled by compressed air. The air brush, when properly used, is capable of rendering a degrade with many different degrees of transition and a variety of shading colors and locations. The fundamental drawback of the air brush lies in its need for a highly skilled operator or artist and a large amount of time-consuming manual manipulation. In addition, once a degrade pattern is formed by an air brush, minor changes to the pattern are extremely difficult, thus requiring the artist to often submit a marginally acceptable pattern or to start over and produce an entirely new degrade pattern.
It was with this understanding of the problems and drawbacks with the prior art that the present invention was made.